diff --git a/NTPClient.cpp b/NTPClient.cpp
index 15dc9e4..07adce7 100644
--- a/NTPClient.cpp
+++ b/NTPClient.cpp
@@ -25,7 +25,7 @@ NTPClient::NTPClient(UDP& udp) {
   this->_udp            = &udp;
 }
 
-NTPClient::NTPClient(UDP& udp, int timeOffset) {
+NTPClient::NTPClient(UDP& udp, long timeOffset) {
   this->_udp            = &udp;
   this->_timeOffset     = timeOffset;
 }
@@ -35,13 +35,13 @@ NTPClient::NTPClient(UDP& udp, const char* poolServerName) {
   this->_poolServerName = poolServerName;
 }
 
-NTPClient::NTPClient(UDP& udp, const char* poolServerName, int timeOffset) {
+NTPClient::NTPClient(UDP& udp, const char* poolServerName, long timeOffset) {
   this->_udp            = &udp;
   this->_timeOffset     = timeOffset;
   this->_poolServerName = poolServerName;
 }
 
-NTPClient::NTPClient(UDP& udp, const char* poolServerName, int timeOffset, int updateInterval) {
+NTPClient::NTPClient(UDP& udp, const char* poolServerName, long timeOffset, unsigned long updateInterval) {
   this->_udp            = &udp;
   this->_timeOffset     = timeOffset;
   this->_poolServerName = poolServerName;
@@ -135,7 +135,7 @@ bool NTPClient::updated() {
   return (_currentEpoc != 0);
 }
 
-unsigned long NTPClient::getEpochTime() {
+unsigned long NTPClient::getEpochTime() const {
   return this->_timeOffset + // User offset
          this->_currentEpoc + // Epoc returned by the NTP server
          ((millis() - this->_lastUpdate + (_currentFraction / FRACTIONSPERMILLI)) / 1000); // Time since last update
@@ -153,20 +153,20 @@ unsigned long long NTPClient::getEpochMillis() {
   return epoch;
 }
 
-int NTPClient::getDay() {
+int NTPClient::getDay() const {
   return (((this->getEpochTime()  / 86400L) + 4 ) % 7); //0 is Sunday
 }
-int NTPClient::getHours() {
+int NTPClient::getHours() const {
   return ((this->getEpochTime()  % 86400L) / 3600);
 }
-int NTPClient::getMinutes() {
+int NTPClient::getMinutes() const {
   return ((this->getEpochTime() % 3600) / 60);
 }
-int NTPClient::getSeconds() {
+int NTPClient::getSeconds() const {
   return (this->getEpochTime() % 60);
 }
 
-String NTPClient::getFormattedTime() {
+String NTPClient::getFormattedTime() const {
   unsigned long rawTime = this->getEpochTime();
   unsigned long hours = (rawTime % 86400L) / 3600;
   String hoursStr = hours < 10 ? "0" + String(hours) : String(hours);
@@ -190,7 +190,7 @@ void NTPClient::setTimeOffset(int timeOffset) {
   this->_timeOffset     = timeOffset;
 }
 
-void NTPClient::setUpdateInterval(int updateInterval) {
+void NTPClient::setUpdateInterval(unsigned long updateInterval) {
   this->_updateInterval = updateInterval;
 }
 
@@ -202,6 +202,10 @@ void NTPClient::setUpdateCallback(NTPUpdateCallbackFunction f) {
   _updateCallback = f;
 }
 
+void NTPClient::setPoolServerName(const char* poolServerName) {
+    this->_poolServerName = poolServerName;
+}
+
 void NTPClient::sendNTPPacket() {
   // set all bytes in the buffer to 0
   memset(this->_packetBuffer, 0, NTP_PACKET_SIZE);
diff --git a/NTPClient.h b/NTPClient.h
index 8163ba1..94470cc 100644
--- a/NTPClient.h
+++ b/NTPClient.h
@@ -18,12 +18,12 @@ class NTPClient {
     UDP*          _udp;
     bool          _udpSetup       = false;
 
-    const char*   _poolServerName = "time.nist.gov"; // Default time server
+    const char*   _poolServerName = "pool.ntp.org"; // Default time server
     int           _port           = NTP_DEFAULT_LOCAL_PORT;
-    int           _timeOffset     = 0;
+    long          _timeOffset     = 0;
 
-    unsigned int  _updateInterval = 60000;  // In ms
     unsigned int  _retryInterval  = 1000;   // In ms
+    unsigned long _updateInterval = 60000;  // In ms
 
     unsigned long _currentEpoc    = 0;      // In s
     unsigned long _currentFraction = 0;     // In 1/(2^32) s
@@ -39,10 +39,17 @@ class NTPClient {
 
   public:
     NTPClient(UDP& udp);
-    NTPClient(UDP& udp, int timeOffset);
+    NTPClient(UDP& udp, long timeOffset);
     NTPClient(UDP& udp, const char* poolServerName);
-    NTPClient(UDP& udp, const char* poolServerName, int timeOffset);
-    NTPClient(UDP& udp, const char* poolServerName, int timeOffset, int updateInterval);
+    NTPClient(UDP& udp, const char* poolServerName, long timeOffset);
+    NTPClient(UDP& udp, const char* poolServerName, long timeOffset, unsigned long updateInterval);
+
+    /**
+     * Set time server name
+     *
+     * @param poolServerName
+     */
+    void setPoolServerName(const char* poolServerName);
 
     /**
      * Starts the underlying UDP client with the default local port
@@ -81,10 +88,10 @@ class NTPClient {
      */
     bool forceUpdate();
 
-    int getDay();
-    int getHours();
-    int getMinutes();
-    int getSeconds();
+    int getDay() const;
+    int getHours() const;
+    int getMinutes() const;
+    int getSeconds() const;
 
     /**
      * Changes the time offset. Useful for changing timezones dynamically
@@ -95,7 +102,7 @@ class NTPClient {
      * Set the update interval to another frequency. E.g. useful when the
      * timeOffset should not be set in the constructor
      */
-    void setUpdateInterval(int updateInterval);
+    void setUpdateInterval(unsigned long updateInterval);
 
     /**
      * Set the retry interval to another frequency in ms
@@ -105,12 +112,12 @@ class NTPClient {
     /**
      * @return time formatted like `hh:mm:ss`
      */
-    String getFormattedTime();
+    String getFormattedTime() const;
 
     /**
      * @return time in seconds since Jan. 1, 1970
      */
-    unsigned long getEpochTime();
+    unsigned long getEpochTime() const;
 
     /**
      * @return time in milliseconds since Jan. 1, 1970
diff --git a/README.md b/README.md
index af9802a..6c8c07a 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@ const char *password = "<PASSWORD>";
 
 WiFiUDP ntpUDP;
 
-// By default 'time.nist.gov' is used with 60 seconds update interval and
+// By default 'pool.ntp.org' is used with 60 seconds update interval and
 // no offset
 NTPClient timeClient(ntpUDP);
 
diff --git a/keywords.txt b/keywords.txt
index 1430d04..6f7bc6f 100644
--- a/keywords.txt
+++ b/keywords.txt
@@ -18,3 +18,6 @@ getMinutes	KEYWORD2
 getSeconds	KEYWORD2
 getFormattedTime	KEYWORD2
 getEpochTime	KEYWORD2
+setTimeOffset	KEYWORD2
+setUpdateInterval	KEYWORD2
+setPoolServerName	KEYWORD2